Magnetic Flux Calculation in a Novel Linear-Rotary Electromagnetic Actuator Using 3D Magnetic Equivalent Circuit

A novel linear-rotary electromagnetic actuator (LREA) intended for the application in dog clutches as a shifting actuator is proposed in this paper. The main novelty of the LREA is the possibility to synchronize the speeds of rotating shafts without mechanical contact between them, which is not possible in common clutches of this type. In rotary operation, the speeds are synchronized magnetically, and a mechanical coupling of the shafts is achieved in linear operation. The actuator has a very simple construction comparing with other LREAs. The working principle and the magnetic flux distribution are described in detail. A 3D magnetic equivalent circuit (MEC) was built to calculate the complex three-dimensional magnetic flux and make stochastic optimization of the geometry possible. A mesh-based system of equations is developed based on the MEC and the flux linkage and torque were calculated analytically. Finally, a 3D model of the proposed actuator with the same dimensions is simulated using 3D finite element analysis (FEA). The analytically obtained results are very close to the FEA results. The developed analytical model can be used for the design optimization of the presented LREA avoiding very large time consumption required for the optimization with 3D FEA. The results of the optimization will be presented in a following publication.